package com.suprNotes;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;

public class PredicateLayout extends ViewGroup {

    private int line_height;

    public static class LayoutParams extends ViewGroup.LayoutParams {
        public final int horizontal_spacing;
        public final int vertical_spacing;
        public LayoutParams(int horizontal_spacing, int vertical_spacing) {
            super(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
            this.horizontal_spacing = horizontal_spacing;
            this.vertical_spacing = vertical_spacing;            
        }
    }

    public PredicateLayout(Context context) {
        super(context);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        
        assert(MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED);
        assert(MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

        final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
        final int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom(); 
        final int count = getChildCount();
        int line_height = 0;

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                
                child.measure(
                        MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST),
                        MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST));

                line_height = Math.max(line_height, child.getMeasuredHeight() + lp.vertical_spacing);
            }
        }
        this.line_height = line_height;
        setMeasuredDimension(width, height);
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(1, 1);
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        if (p instanceof LayoutParams)
            return true;
        return false;
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int count = getChildCount();
        final int width = r - l;
        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final int childw = child.getMeasuredWidth();
                final int childh = child.getMeasuredHeight();
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height;
                }
                child.layout(xpos, ypos, xpos + childw, ypos + childh);
                xpos += childw + lp.horizontal_spacing;
            }
        }
    }
}

